Crackling and static in the right channel [resolved]

C

Cowwe

New member
On my stock crack I have recently had this issue where the right channel makes some loud static and crackling noises. It may go away if I remove and reinsert the power tube or switch it with a different one, but every tube gives me this problem now (even the stock 6080 that used to work fine).
Moving the tube around while the amp is on changes this noise for the better or worse. It doesn't always happen, but when it does it's so loud that I have to turn my Crack off.
Is it safe to assume that I might need to reheat some joints in the power tube side?
 
As a general suggestion, if the noise does change a lot, coming and going when I move the power tube, is it an indication that the problem might be in that tube's socket? Or it could also be any other solder joint?
 
I have tried reheating the joints in the tube socket that might have been less than ideal but it hasn't fixed my issue. I keep having loud static and crackling only in the right channel, no matter what tube I try on.
I have checked voltages and everything measures within the standards.
Before yesterday I have had this problem occasionally, but removing/switching power tubes usually made it go away.
Yesterday I have installed the 2 diodes as ground break to shield from usb noise, and it did work perfectly at first.
Later in the night and today the noise does not go away no matter what I do, and it's so loud that the amplifier is unusable.
I know it has to be a mistake I made somewhere, but it feels so disheartening to keep having so many problems with my kit after putting in all the effort that I could..
I have tried messing with the cables but that did not do anything.
I am going to post some pictures. Please let me know if you have any idea what else I can do.
https://imgur.com/a/z68PjJd
 
I have been testing things out a little more:
Just now I could hear the same static coming and going a bit more quietly, but then this happened:
After a minute it looked like the tubes' glow got a little fainter but quickly regained strength.
One more minute after that my Crack just turned off and won't turn on again.
 
I have switched the first tube with a second and now the amp turns on again, with the noise in the right channel remaining.
Switched second and first around again and it lights up again. I really don't understand anymore.
 
One more report: I have tried the chopstick test and tapped every solder joint in my amp, and couldn't notice any reaction in the intermittent buzzing.
Tapping the chassis or the tubes also doesn't seem to bring any reaction.
 
You are either using lead free solder or a cold iron.  If you're using lead free solder, get some leaded solder.  If you're using leaded solder, turn the iron all the way up.

The solder joints back by the power switch would be of very minimal concern if you are rocking the 6080 and that's making noise.  Perhaps you could take some more build photos of the rest of the amp and post them.
 
I am using 60% leaded solder, as was reccommended. I also tried keeping my iron set to maximum, or close to it, during most of the process.
Here are some pictures. Please let me know if you want to see anything more closely.
https://imgur.com/a/4gpyDsY
 
Here are some close ups on the socket. https://imgur.com/a/tR906FF
I'm going to look into 10L.
Looking closer I'm thinking 21L might need some solder too (the last picture).
I'm going to take a break for today (damn you timezones), but thank you for the support until now. Earlier today I was really despairing.
 
No despair necessary. Bottlehead support ranks right up there with the very best you will find anywhere. QFT.
 
What you can do is to plug the cheapest headphones you have into the Crack (they can be low impedance headphones, that's OK), then poke around the circuit with a wooden chopstick while the amp is running to see if you can set the noise off.  This is what I do when I have a noise issue that I'm having a hard time tracking down.
 
Unfortunately as I reported yesterday I have already tried tapping away with a chopstick while listening for reactions in the sound, but I couldn't tell if there was any change.
 
I am going to give the chopstick test another try once I get home from work. For the meantime, could the fact that my issue is only on the right channel highlight some possibilities as to where the problem could lie? The left channel is completely fine.
 
You can also rock the tube with those headphones in and look for two components moving differently that would otherwise be soldered together.
 
I have an update (I'm afraid it might be a pretty bad one).
I once again closely inspected my kit looking for any loose wires and poorly soldered joints, but couldn't find anything that caught my eye so I decided to move on to the chopstick test.
I had just my 12au7 in its socket while the 6080 wasn't inserted, and the power switch was off. I plugged the amp in, intending to then insert the 6080 and turn the crack on, but before I could I got shocked through (I'm positive but not 100% sure) the chassis.
 
The chassis is earthed, so it's unlikely that you'd be shocked by the chassis, but it is possible that you were touching part of the IEC power entry module when you plugged the power cord in.  I would plug the cord into the Crack first, then the wall.
 
Today I went through testing everything once again.
Resistances measured correctly. The amp turned on correctly and the voltage check is within the limits:

1) 84  2) 170  3) 0  4)170  5)80
6) 0  7)104  8)0    9)106  10)0

I went on to plug a pair of old headphones. The crackling was still there so I tried tapping on each solder joint with a chopstick. Nothing made any notable difference in the noise.
The one thing that made the difference was rocking the 6080 tube until the noise went away.
Tonight I'm going to try to listen with different tubes and see whether it really was just the tube pins not making contact all along.
 
You must log in or register to reply here.

Similar threads

Spargle Spike
Periodic Static in right ear [resolved]
Replies
3
Views
1K
Spargle Spike
Spargle Spike
A
static/crackling in left channel
2
Replies
25
Views
69K
Paul Birkeland
Paul Birkeland
R
New crack - right channel slightly quiet Voltage different but in range
Replies
2
Views
2K
Paul Birkeland
Paul Birkeland
superdonkey
[FIXED] terminal 7 is OL and OB on Speedball is OL. My bad....
Replies
13
Views
3K
superdonkey
superdonkey
P
Right channel hiss [resolved]
Replies
2
Views
2K
Pharane0
P
Back
Top